THE IDENTIFICATION OF THE SPECIES IN THEWILD FRYOF THE MIDDLE WATERS OF THE YANG.TZE RIVER

The known fishes of the Yang-tze River amount to over 200 species.But each year the fishery for fry is limited to only four species,the so-calledpond-culture fishes: Mylopharyngodon piceus(Rich.),Ctenopharyngodon idellus(C. V),Hypophthalmich- thys molitrix(C..V.),and Aristichthys nobilis(Rich.).The rest are calledwild fry,and hitherto have not been utilized by fish culturists.Since Liberation there have been rapid advances,both in method and productivity,in our country in freshwater fish culture,so it has become increasingly difficult to meet the growing demand if supplies of fry are to depend only upon these four species ofpond-culture fishes.It has become an urgent necessity to augment the number of species for pond culture.The present work has been carried out in accordance with this need.Owing to the careful observation of generations of experienced fishery workers,it is now a common routine to identify the early fry of the four economically important species of Mylopharyngodon,Ctenopharyngodon,Hypophthalmichthys and Aristicthys.But hitherto it has not been possible to identify most of thewild fry.Therefore,in order to select certain of these species for culture,it is first of all necessary to become familiar with the characters and behaviour of each of the species composing thewild fry,and these have been described in the present paper.